Publications and other reference materials referred to herein, including reference cited therein, are incorporated herein by reference in their entirety and are numerically referenced in the following text and respectively grouped in the appended Bibliography which immediately precedes the claims.
Acute respiratory failure is an emergency medical condition in which there is extremely low oxygen level or extremely high carbon dioxide level in an individual's blood. In acute respiratory failure the lungs can become unable to replenish oxygen supplies because of an airway obstruction or the presence of excessive fluids. Acute respiratory failure is usually fatal if an individual does not receive immediate medical services. Doctors or emergency medical technicians will try to open a sufficient airway, supply oxygen, and determine any underlying causes in order to provide additional treatment. The onset of an acute or chronic respiratory failure may occur due to an asthma attack, smoke inhalation, choking, or drowning, or many other pulmonary diseases that obstruct the intake of air.
Respiratory failure is a common name given to a wide variety of medical situations. For example, Chronic Obstructive Pulmonary Disease (COPD) is now the third leading cause of death globally. One out of every four men and one of every six women who live to be 95 years old will develop COPD. COPD is an umbrella term used to describe lung disease associated with airflow obstruction. Most generally, emphysema, and chronic bronchitis, either alone or combined, fall into this category. In the US, there are over 1.5 million emergency department visits by adults, over 725,000 hospitalizations due to COPD and over 140,000 COPD-related deaths (2008). As of 2009, 300 million people worldwide were affected by asthma leading to approximately 250,000 deaths per year [1]. It is estimated that asthma has 7-10% prevalence worldwide [2]. Asthma is responsible for more than 2 million visits to the emergency department (ED) in the United States each year, with 1 in 4 patients requiring admission to a hospital. Annually there are 5,000 to 6,000 asthma-related deaths in the United States, many occurring in the pre-hospital setting. Severe asthma accounts for approximately 2% to 20% of admissions to intensive care units, with up to one third of these patients requiring intubation and mechanical ventilation [3].
Drowning is responsible for more than 500,000 deaths each year worldwide. Drowning is a leading preventable cause of unintentional morbidity and mortality. According to the 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science, The most important and detrimental consequence of submersion is hypoxia; therefore, oxygenation, ventilation, and perfusion should be restored as rapidly as possible
Other pathologies which may result in respiratory failure include Angioedema of the airway due to Anaphylaxis; Pharyngeal infections; upper airway foreign body; Rib fractures with Flail chest; Pulmonary COPD or Asthma exacerbations; Pulmonary embolism; Pneumothorax; Pulmonary or distant infections with developed ARDS; Pulmonary contusion or other lung injury; Pulmonary insufficiency due to Cardiac failure or acute coronary syndrome; pulmonary edema; Arrhythmia; Stroke and other CNS pathologies. Oxygen is a potent and readily available treatment for many of the above causes of dyspnea and should be administered liberally.
According to the AHA 2010 guidelines, patients with severe life-threatening asthma require urgent and aggressive treatment with simultaneous administration of oxygen, bronchodilators, and steroids. Short-acting β-agonists provide rapid, dose-dependent bronchodilation with minimal side effects. Salbutamol, or albuterol, is a common short-acting Short-acting β-agonists used for the relief of bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease. It is marketed as Ventolin among other brand names.
Salbutamol sulfate is commonly the form used for inhalers, for a direct effect on bronchial smooth muscle. In this form of delivery, the maximal effect of salbutamol can take place within five to 20 minutes of dosing, though some relief is immediately seen. Salbutamol is typically used to treat bronchospasm due to allergy or asthma attack, exercise-induced bronchospasm, as well as chronic obstructive pulmonary disease, and cystic fibrosis.
Systemic corticosteroids are the only treatment for the inflammatory component of asthma proven to be effective for acute asthma exacerbations. The use of inhaled steroids may hasten the resolution of airflow obstruction. In fact, Inhaled corticosteroids (ICS), or inhaled steroids, are the most potent anti-inflammatory controller medications available for the treatment of asthma. Steroids May also be extremely effective for the treatment of respiratory failure that is induced by cerebrovascular accident (CVA) also known as stroke.
Vasopressor agents that are given during CPR aim to improve aortic diastolic pressure. Consequently, increases in coronary and cerebral perfusion pressures enhance both myocardial and cerebral blood flow and improve survival. Adrenergic agonist; adrenaline (epinephrine) is routinely used to enhance cerebral and myocardial blood flow by preventing arterial collapse and by augmenting aortic diastolic pressure through alpha 1 and 2 receptors [6]. These drugs, if directly provided to the patient's mouth in the right timing, may very well be the difference between life and death.
In general, there are two types of critical care devices currently available to the public: first aid kits, including bandages and the like, and an Automated External Defibrillator (AED) being a portable electronic device that applies electrical shock therapy for the treatment of cardiac arrhythmias. Oxygen therapy equipment for active ventilation of a patient, is in most cases only available to medical professional providers of paramedics and doctors in the EMS or hospital, and is not available to non-medical personal.
In current emergency care, tracheal intubation is still the main practice for treating acute respiratory failure by paramedics and professional medical care giver. Tracheal intubation is a highly invasive and extremely uncomfortable medical procedure that requires skills, training and experience, and it is associated with significant and often fatal complications such as loss of speech, pulmonary aspiration of stomach contents, bradycardia and tracheal injury and perforation.
Non-invasive ventilation (NIV) is defined as ‘delivery of ventilatory support via the patient's upper airway using a mask or similar device’ and includes both continuous positive airway pressure (CPAP) and non-invasive positive pressure ventilation (NPPV). NIV was initially used to treat chronic obstructive pulmonary disease related respiratory failure and prevent the need for mechanical ventilation and the attendant complications associated with invasive ventilation but is now emerging as a useful alternative treatment strategy to mechanical ventilation in a number of different clinical situations. Worldwide, the use of NIV has more than doubled in the past 10 yr. In the UK where the previous decade has seen a disproportionate increase in level 2 critical care beds, NIV use has risen steadily. Yet, large international geographical variations remain and NIV use remains relatively low in areas such as North America.
Due to the substantial mortality and morbidity associated with tracheal intubation, the use of Non-Invasive Ventilation (NIV) is gradually increasing; currently it is mainly used in hospital wards and in the long term home care treatment of chronic respiratory problems. NIV has its own drawbacks—if the patient is unconscious NIV may not be effective enough in supplying oxygen to the patient, and, since there must be created a perfect seal to the face for keeping the air pressure inside the mask cavity, a patient who vomits may be at risk of aspiring the fluids if they are not cleared from the mask, or if the mask is not removed quickly from his face. Non-invasive ventilation is still a challenge for medical practice.
Firemen, police officers, or lifeguards acquire substantial training in basic or advanced life support. They are trained to perform CPR and use a defibrillator, and although immensely helpful, they are unable to provide emergency oxygen due to lack of appropriate solutions. Performing tracheal intubation is carried out only by highly experienced and professional medical teams in a well-equipped environment such as the ambulance or the hospital ward, while non-invasive solutions are unfortunately not available outside of such settings, e.g. in public spaces or swimming pools.
An Automated External Defibrillator (AED), which is commonly available in public spaces, is used in cases of life threatening cardiac arrhythmias which can lead to cardiac arrest. As accepted in medical practice, shockable cardiac arrhythmias include ventricular fibrillation and pulseless ventricular tachycardia (VF/VT). In both these types of shockable cardiac arrhythmia, the heart is electrically active, but in a life-threatening, dysfunctional pattern. In ventricular tachycardia, the heart beats too fast to effectively pump blood. In ventricular fibrillation, the electrical activity of the heart is chaotic, preventing the ventricles from effectively pumping blood. The AED provides electrical shock to a patient in cardiac arrhythmias (VF/VT) in order to re-synchronize the electric activity of the heart muscles, and revive the heart.
In respiratory failure, not enough oxygen is reaching the lungs to properly oxidize the blood and clear the carbon dioxide. At first, the activity of the heart remains normal, so the heart is pumping and circulating the blood throughout the body. But as the circulating blood is not oxygenated properly in the lungs due to obstruction in respiration, the oxygen blood saturation decreases rapidly, until reaching a certain low oxygen level at which the heart starts to fibrillate. Doctors refer to such fibrillation as non-cardiac VF, because this kind of fibrillation does not originate from a cardiac problem but from a respiratory problem. Although this kind of fibrillation is also treated by electric shock, the chances of surviving such non-cardiac fibrillation is much lower than in cardiac VF, as non-cardiac VF is indicative of a poor clinical situation and its success is much dependent on the oxygen level in the blood and on medications
Cardiac defibrillation therapy is quite effective if applied within a short time window of 5-8 min from the time of cardiac VF/VT incidence. Studies show a 71% survival rate in witnessed cardiac arrest in casinos or airports, where AED is readily available, and the patients were treated within three minutes. After eight minutes survival rate drop dramatically.
In contrast, non-cardiac VF defibrillation has much lower chance for success, as it is the outcome of very low oxygen blood saturation and is indicative of a poor clinical condition. In fact, without restoring ventilation and elevating blood oxygen level, there is little chance of saving the patient's life.
In order to increase blood oxygen level quickly and improve the success rate of defibrillation in a non-cardiac VF, oxygen must be applied and an effective CPR must be carried out. The more effective the CPR, the faster the blood oxygen level rise until reaching a level that enables an effective shock by the AED.
The efficiency of carrying out a cardiopulmonary resuscitation (CPR) procedure is critical to the survival chances of the patient [4]. However, it is difficult to estimate CPR efficiency, especially outside a medical center.
Hence, efforts are made to assess CPR efficiency in order to improve the rate of successful CPR procedures. The company Cardiaid for example supplies a device that monitors pulse and breathing in the patient during CPR [5]. In another approach, International Patent Application WO2012/065167 discloses sensing cyclical activities by a rescuer carrying out CPR and summarizing them, and U.S. Pat. No. 6,827,695 discloses processing acceleration signals to produce an accurate estimate of the actual depth of chest compressions. These mechanical solutions try to overcome the basic problem, that vital signs are not reliable indicators as they become very chaotic and non-informative during CPR.
To summarize, as AED's are helpful in only a fraction of emergency situations, and oxygen therapy is unavailable to the non-medical care-giver, there is a pressing need for a system that can provide an integrated solution for both cardiac and respiratory emergency situations that is non-invasive and adapted to the needs of field care, and operable by minimally trained personal.
The purpose of the present invention is to provide the basically trained, semi-professional such as a life guard or police officer, with an advanced, non-invasive medical device, that supports non-invasive ventilation in an acute respiratory failure such as drowning, provides real-time feedback on CPR efficiency, optimizes the application of electric shock, and enables saving lives in a myriad of situations that were not treatable so far in an out-of-hospital field setting.
Further purposes and advantages of this invention will appear as the description proceeds.